The present invention relates to systems for generating special effects sparks for shows, theme park rides and the like. These sparks, for example, can simulate sparks generated in a large electrical short or those generated by the friction of metal-to-metal impact.
A system known in the prior art for generating special effects sparks for theme park rides and shows is shown in FIGS. 1 and 2 generally at 30. Referring thereto, system 30 is shown to include a Molten Inert Gas (MIG) welder gun 32 which is operatively connected to a power control unit 34. A spool of titanium wire 36 held in the body of the gun is fed out the gun nozzle 38 during the operation thereof. The wire is fed out to a pulley 40, similar to those found on automobiles or lawn mowers, and which is rotated by an air motor 42 to which the pressurized air is fed through air lines 44 connected at their opposite ends to the control unit 34. The pulley 40 is grounded by a rocker arm or motor brush 50 and a ground wire 52. This grounding is important since the gun 32 is at a much higher voltage and amperage potential than is the pulley 40. While the pulley 40 is at ground, the wire via the gun 32 is at between seventy-five and two hundred amps and between five and fifteen volts.
As the wire is fed out of the gun 32 it explodes when it hits the rotating pulley 40. This is because it is trying to weld onto it but it cannot because the pulley 40 forms a rapidly moving surface. That is, instead of welding to the pulley 40, molten wire sparks are produced. Compressed air is blown out through a nozzle 54 towards these sparks propelling them away in a stream or shower. In other words, the compressed air blows the small fragments of molten slag produced as the wire is vaporized out into the air.
By changing the type and size of wire on the spool 36 a different character of sparks can be produced. The shower of sparks can also be varied by adjusting the air pressure from nozzle 54. Additionally, the shower effect can be varied by varying the amperage of the MIG gun 32 and/or by increasing the speed of the wire feed out therefrom.
There are a number of problems with this spark generating system, including the costs of the wire itself. The main problem is that titanium slag builds up on the pulley 40. This requires that the pulley 40 either be replaced or that the slag be scraped off with a wire brush, both tasks being maintenance intensive. If too much slag builds up then the nozzle 54 blocks and the wire jams up in the gun 32. It is then necessary to go to the time and expense of replacing the tip of the nozzle 54 and unjamming the wire within the gun 32.
In addition to these expenses and maintenance problems, there is also a small safety hazard due to the electrical operation of the gun, though the shock potential is not great given the relatively low voltages used. The system 30 is also large and awkward, not fitting into small areas required in many shows.
It was also difficult with the prior art system 30 to not only maintain repeatability of spark characteristics through multiple cycling over long periods of time, but also to produce the desired spark characteristics in the first instance. Coarse sparks convincingly simulating the burning of parts in an electrical fire were very difficult if not impossible to produce with that system.
Other means known for producing "sparking" effects are shown in U.S. Pat. Nos. 1,653,701 ('701), 1,781,516 ('516) and 2,198,177 ('177). (These three patents and all other patents mentioned anywhere in this disclosure are hereby incorporated by reference in their entireties.) The '177 and 516 patents show toys producing only a few sparks each with each use thereof and certainly not the volume of sparks that are required to be viewed at a distance by audiences of theme park rides or shows. They may produce thirty or so pin-tip size sparks which travel out only a few inches or maybe a foot. Further, these sparking toys are not adapted to automatically and consistently produce sparks of certain characteristics and to be able to vary the spark shower. The '701 device shows a rotating grinder and a plurality of metal pieces applied simultaneously against the grinder to produce a sun-wheel fireworks type of luminous display. It does not simulate a shower of sparks, similar to those from electrical fires or train wrecks. It also does not propel the sparks out in a shower or allow for effective control and adjustment of the spark characteristics.